The present invention relates to an apparatus and a method for resource recovery from organic substances such as organic wastes containing biomass (biological resource), utilizing superheated steam.
The inventors of the present invention have put their efforts to research and development of technologies for utilizing superheated steam to a high degree for many years, and have succeeded in development and commercialization of, for example, novel food processing methods and apparatuses that allow the characteristics of atmospheric pressured heated steam to be utilized as a food processing technique.
In recent years, under the circumstances that scientific and basic research regarding superheated steam is advancing, the inventors of the present invention found that organic wastes can be reduced by carbonization, utilizing various characteristics of the superheated steam as a thermal radiation gas, an anoxic gas and a reducing gas, and proposed a novel method for producing a carbide and an apparatus thereof, utilizing the characteristics of the superheated steam (see the specification and the drawings of Japanese Patent Application No. 11-309982)
Conventionally, various attempts for resource recovery from food wastes or the like have been made by pulverizing and drying food wastes or the like, and performing carbonization with a carbonizing apparatus and cooling for production into various carbonized products.
However, in this method, a regular fuel for the carbonizing apparatus is used, and food wastes or the like is carbonized by dry-distillation, utilizing the energy of the fuel. Therefore, this method has the following problems: There is a high possibility of generation of hazardous substances in the dry-distilled gas; Carbonization and cooling take a long time; A large amount of energy consumption is required; The apparatus is of a large-scale batch system, and the obtained carbonized products are expensive because of a high cost heat source.
On the other hand, to generate the superheated steam, conventionally, it is general that steam generated by a boiler is heated with a heater or the like to produce superheated steam controlled to a predetermined temperature.
To produce hot water with a high temperature, a boiler can be used, and it is also known that an electrically powered high temperature heat storage reservoir utilizing inexpensive night-time electricity is used and hot water is produced in the high temperature heat storage reservoir.
Thus, conventionally, various research and development have been made and many efforts have been reported, regarding the production of carbonized products by dry-distilling organic substances containing biomass (biological resources) of food wastes or the like with a carbonizing apparatus, the production of high temperature hot water by utilizing night-time electricity, utilization of the organic substances gasified in a large-scale gasification furnace as regular combustion energy or the like. However, these methods have various problems to be solved, such as treatment of hazardous substances contained in the dry-distilled gas, inefficiency of a large scale batch system, and much time and cost for the treatment. Therefore, there is a strong demand for solving these problems and developing a new system for resource recovery that immediately can be applied to resource recovery from organic substances.
Under these circumstances, the inventors of the present invention have studied hard to develop a new system that permits resource recovery from organic substances and consequently constructed a new system that converts energy obtained by gasifying organic resources to superheated steam and a new carbonizing system that carbonizes organic substances using the above system for resource recovery, and thus realized the present invention.
Thus, it is an object of the present invention to provide a new system for carbonization and resource recovery by carbonizing organic substances containing biomass for resource recovery by utilizing superheated steam.
It is another object of the present invention to provide a new system as a heat source for generating superheated steam.
It is still another object of the present invention to provide a new system for converting energy obtained by gasifying organic substances to superheated steam.
It is yet another object of the present invention to provide a new energy conversion system, utilizing a cogeneration including an engine that converts the energy from gasification to electric power and hot water.
Moreover, it is an object of the present invention to achieve effective utilization of the dry-distilled gas generated in a carbonizing furnace in the system for resource recovery by heating the organic substances in the superheated steam.
In order to achieve these objects, the present invention provides an apparatus for resource recovery from an organic substance for gasification containing biomass by converting energy obtained by gasifying the organic substance for gasification to superheated steam. The apparatus of the present invention includes a gasification furnace for generating a combustible gas containing at least one of hydrogen and carbon monoxide from the organic substance for gasification; a cogeneration including an engine that uses the combustible gas generated by the gasification furnace as a fuel, an electric generator driven by the engine, and a radiator for generating hot water by heating water by cooling the engine; and superheated steam generating means for generating superheated steam from the hot water generated by the radiator of the cogeneration. The superheated steam generated by the superheated steam generating means is supplied to another apparatus.
Furthermore, the apparatus of the present invention may include a carbonization furnace for generating a dry-distilled gas and a carbide by heating an organic substance for carbonization containing biomass in the superheated steam generated by the superheated steam generating means.
In the above invention, in the gasification furnace, a combustible gas is generated from the organic substance for gasification containing biomass, and this combustible gas is supplied to the cogeneration. In the cogeneration, the combustible gas from the gasification furnace is combusted in the engine, so that the engine is operated. This engine drives an electric generator to output electric power, and water is heated by heat exchange in the radiator to produce hot water. In the superheated steam generating means, atmospheric pressured superheated steam is generated from the hot water produced by the radiator of the cogeneration, and this superheated steam is supplied to another apparatus. Furthermore, the superheated steam generated by the superheated steam generating means is supplied to the carbonization furnace, and in this carbonization furnace, an organic substance for carbonization containing biomass is heated in the superheated steam so that a dry-distilled gas and a carbide are generated. Therefore, the present invention provides the following distinguished advantages: (1) A novel system for carbonizing organic substances for resource recovery utilizing superheated steam can be obtained; (2) A conventional treatment of organic substances containing biomass commonly is performed by combustion, which causes problems such as air pollution due to exhaust gas, whereas the present invention can convert energy obtained in the system directly to superheated steam, which is clean and low cost, and can recover the organic substances as the superheated steam without generating hazardous substances; (3) A new system for converting energy obtained by gasifying organic wastes to superheated steam can be obtained; (4) Since the cogeneration allows high-output energy to be collected with a generated gas with a lower calorie than that of town gas, the gasification. furnace can be small; (5) Since the superheated steam can be generated and supplied without using a boiler or the like, the apparatus can be small; (6) A new system for treating organic substances free from combustion can be obtained; and (7) It is expected that the present invention will be the main stream of treatment of organic substances as an environment friendly treatment system.
Furthermore, similarly, the present invention provides an apparatus for resource recovery by carbonizing an organic substance for carbonization containing biomass with superheated steam. The apparatus of the present invention includes a cogeneration including an engine that uses a combustible gas containing at least one of hydrogen and carbon monoxide as a fuel, an electric generator driven by the engine, and a radiator for generating hot water by heating water by cooling the engine; superheated steam generating means for generating superheated steam from the hot water generated by the radiator of the cogeneration; and a carbonization furnace for generating a dry-distilled gas and a carbide by heating the organic substance for carbonization in the superheated steam generated by the superheated steam generating means and generating the combustible gas by heating the carbide in the superheated steam.
In this invention, similarly to the above invention, when a combustible gas containing at least one of hydrogen and carbon monoxide is supplied to the cogeneration, the combustible gas is combusted in the engine of the cogeneration, so that the engine is operated. This engine drives an electric generator to output electric power. Moreover, water is heated by heat exchange in the radiator to produce hot water. In the superheated steam generating means, atmospheric pressured superheated steam is generated from the hot water produced by the radiator of the cogeneration, and this superheated steam is supplied to the carbonization furnace, and in this carbonization furnace, an organic substance for carbonization is heated by the superheated steam at an anoxic state, a low temperature, and a high calorie for dry-distillation and carbonization to generate a dry-distilled gas and a carbide. Then, the carbide carbonized in this carbonization furnace is further heated by the superheated steam and gasified. Thus, the combustible gas is generated, and this combustible gas and the dry-distilled gas are supplied to the engine of the cogeneration. Therefore, the present invention allows the dry-distilled gas to be harmless by heating the dry-distilled gas in the engine in the cogeneration. Moreover, the combustible gas that can be used as a fuel for the engine of the cogeneration is generated from the generated carbide in the carbonization furnace. Thus, the carbonization furnace also serves as the gasification gas, and therefore the apparatus can be small.
Furthermore, the superheated steam generating means is constituted by an electrically powered superheated steam generator that uses electric power generated by the electric generator of the cogeneration as heating energy. In other words, the electrically powered superheated steam generator allows the electric power generated by the electric generator of the cogeneration to be used as the heating energy to generate the superheated steam from the hot water generated by the radiator of the same cogeneration, and thus the electric power can be utilized effectively, and energy saving can be achieved.
Furthermore, the superheated steam generating means may be constituted by a combustion type superheated steam generator that generates superheated steam from hot water by combusting the dry-distilled gas generated in the carbonization furnace. In the combustion type superheated steam generator, the dry-distilled gas generated in the carbonization furnace at the same time of the carbonization of the organic substance is combusted, and this combustion generates the superheated steam from hot water generated by the radiator of the cogeneration. Thus, the dry-distilled gas can be combusted, so that the dry-distilled gas is effectively utilized as the heat energy for generation of the superheated steam and become harmless.
Furthermore, the superheated steam generating means may be constituted by both the combustion type superheated steam generator and the electrically powered superheated steam generator. By using both the electrically powered superheated steam generator and the combustion type superheated steam generator, the ability of generating the superheated steam can be improved.
In this case, the carbonization furnace may be configured so as to heat superheated steam using at least one of an exhaust gas from the engine of the cogeneration and an exhaust gas from the combustion type superheated steam generator as a heat source. With this invention, at least one of an exhaust gas generated by combustion of the dry-distilled gas in the combustion type superheated steam generator and an exhaust gas generated by combustion of a combustible gas in the engine of the cogeneration is supplied to the carbonization furnace, and the superheated steam is heated by the heat of the exhaust gas in the carbonization furnace. Thus, the heat energy of the exhaust gas generated by the combustion of the dry-distilled gas and/or the combustible gas can be effectively utilized as the heat source in the carbonization furnace, so that the dry-distillation and the carbonization of the organic substances with the superheated steam in the carbonization furnace can be facilitated.
It is preferable that the electrically powered superheated steam generator is of a heat storage type where a heat transfer pipe and an electric heater are provided in a high temperature heat storage reservoir having a heat storage material.
It is preferable that the combustion type superheated steam generator combusts the dry-distilled gas together with another fuel. This invention improves the heating ability of the combustion type superheated steam generator.
Furthermore, the apparatus of the present invention may include cooling means for generating acetic acid by cooling the dry-distilled gas generated in the carbonization furnace. Thus, the dry-distilled gas generated at the same time of the carbonization of the organic substance in the carbonization furnace is cooled by the cooling means, and this cooling generates acetic acid. Therefore, the dry-distilled gas can be effectively utilized by converting it to acetic acid. Thus, acetic acid can be produced from the organic substance easily, and the dry-distilled gas can be harmless.
Furthermore, at least a part of the carbide generated by the carbonization furnace may be supplied to the gasification furnace. This invention makes it possible to reuse the carbide generated in the carbonization furnace, and effective utilization of the carbide and energy saving can be achieved.
The apparatus of the present invention may include an exhaust gas boiler for generating saturated steam by heating hot water generated by the radiator of the cogeneration with an exhaust gas from the engine. This invention can generate steam by heating the hot water with the exhaust gas from the engine, so that further effective utilization of the exhaust gas and energy saving can be achieved.
It is preferable that the engine of the cogeneration is a rotary engine. More specifically, even if the combustible gas generated in the gasification furnace or the carbonization furnace has a lower calorie than that of town gas, the rotary engine can use the combustible gas as the fuel without a combustion improver. Thus, the rotary engine is suitable for combusting the combustible gas generated in the gasification furnace or the carbonization furnace.
It is preferable that the carbonization furnace is a continuous type carbonization furnace. This invention provides a carbonization furnace suitable to the system of the present invention.
It is preferable that the apparatus of the present invention includes granulating means for previously molding the organic substance for carbonization into granules before being fed to the carbonization furnace. In this invention, the organic substance containing biomass is fed to the carbonization furnace in the form of granules, and therefore the passage properties and the contact properties of the superheated steam with respect to the organic substance is high in the carbonization furnace. Thus, the carbonization of the organic substance can be performed efficiently. In addition, since the granular organic substance is carbonized keeping its form, the generated carbide can be granular, so that the handling properties can be improved.
The organic substance for gasification to be fed to the gasification furnace is at least one selected from the group consisting of organic resources, carbides, wood and other organic wastes. The organic substance for carbonization to be fed to the carbonization furnace is at least one selected from the group consisting of agricultural wastes including chaff and straw, livestock wastes including fowl droppings and droppings of pigs and cattle, forestry wastes including lumber from thinning, waste wood and bamboo, industrial wastes discharged in a food production process, a brew process or a lumber production process, domestic wastes including food refuse, domestic garbage and waste edible oil, organic resources, waste rubber materials and resins including fiber reinforced resins.
Furthermore, electric power generated by the electric generator of the cogeneration may be supplied to the outside. This invention makes it possible to supply electric power easily by utilizing the energy from gasification of the organic substance.
Furthermore, it is preferable that the temperature of the superheated steam when generating a carbide from the organic substance for carbonization in the furnace for carbonization is 400xc2x0 C. or less.
According to another aspect of the present invention, a method for resource recovery by carbonizing an organic substance for carbonization containing biomass with superheated steam for resource recovery includes a gasification step of generating a combustible gas containing at least one of hydrogen and carbon monoxide from an organic substance for gasification containing biomass; a cogeneration step of operating an engine of a cogeneration using the combustible gas as a fuel to drive an electric generator by the engine and generating hot water by heating water in a radiator; a superheated steam generation step of generating superheated steam from the hot water generated by the radiator; and a carbonization step of generating a dry-distilled gas and a carbide by heating the organic substance for carbonization in the superheated steam.
Furthermore, similarly, a method for resource recovery by carbonizing an organic substance for carbonization containing biomass with superheated steam for resource recovery includes a cogeneration step of operating an engine of a cogeneration using a combustible gas containing at least one of hydrogen and carbon monoxide as a fuel to drive an electric generator by the engine and generating hot water by heating water in a radiator; a superheated steam generation step of generating superheated steam from the hot water generated by the radiator; and a carbonization step of generating a dry-distilled gas and a carbide by heating the organic substance for carbonization in the superheated steam and generating a combustible gas by heating the carbide.
These methods provide the same effects as above, and resource recovery from organic substances containing biomass can be achieved efficiently.
In the superheated steam generation step, the superheated steam may be generated from the hot water using electric power generated by the electric generator of the cogeneration as heating energy. In this case, similarly to the above invention, the superheated steam is generated from the hot water generated by the radiator of the cogeneration using the electric power generated by the electric generator of the cogeneration as the heating energy. Thus, the electric power can be effectively utilized, so that energy saving can be achieved.
Furthermore, in the superheated steam generation step, the superheated steam can be generated from hot water by combustion of the dry-distilled gas generated in the carbonization step as the heating energy. In this invention, the dry-distilled gas generated at the same time of the carbonization of the organic substance in the carbonization step can be combusted so that the dry-distilled gas can be effectively utilized as heat energy for generation of the superheated steam and also become harmless.
Furthermore, it is preferable that at least a part of the carbide generated in the carbonization step is used as a carbide in the gasification step. Thus, the carbide generated in the carbonization step is reused in the gasification step so that effective utilization of the carbide and energy saving can be achieved.
In the superheated steam generation step, the saturated steam may be generated by heating hot water generated by the radiator of the cogeneration with an exhaust gas from the engine. In this invention, since steam can be generated by heating hot water with the exhaust gas from the engine, further effective utilization of the exhaust gas and energy saving can be achieved.
It is preferable that the organic substance for carbonization is previously molded into granules before being heated with the superheated steam in the carbonization step. In this invention, since the organic substance containing biomass is heated in the form of granules, the passage properties and the contact properties of the superheated steam with respect to the organic substance are high in the carbonization step. Thus, the carbonization of the organic substance can be performed efficiently, and the handling properties can be improved.
The organic substance for gasification used for generating the combustible gas in the gasification step is at least one selected from the group consisting of organic resources, carbides, wood and other organic wastes. Furthermore, the organic substance for carbonization heated in the carbonization step is at least one selected from the group consisting of agricultural wastes including chaff and straw, livestock wastes including fowl droppings and droppings of pigs and cattle, forestry wastes including lumber from thinning, waste wood and bamboo, industrial wastes discharged in a food production process, a brew process or a lumber production process, domestic wastes including food refuse, domestic garbage and waste edible oil, organic resources, waste rubber materials and resins including fiber reinforced resins.
Furthermore, it is preferable that the temperature of the superheated steam when generating a carbide from the organic substance for carbonization in the carbonization step is 400xc2x0 C. or less.
This and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying figures.